Sensitized photographic silver halide emulsions

ABSTRACT

A silver halide photographic emulsion containing at least one of the following: 1. a cyanine sensitizing dye represented by the general formula (A)   The dyes have at least one benzimidazole nucleus in which one hydrogen atom of the benzene ring forming the nucleus is substituted by a chlorine atom, and another hydrogen atom of the ring is substituted by a sulfonyl derivative group as shown in the general formulas.

United States Patent [72] inventors Japan [21] Appl. No. 671,232 [22] Filed Sept. 28, 1967 [45] Patented Oct. 26, 1971 [73] Assignee Fuji Shashln Film Kabushiki Kaisha Kanagawa, Japan [32] Priority Sept. 28, 1966 [33] Japan [31] 41/63936 [54] SENSITIZED PHOTOGRAPHIC SILVER HALIDE EMULSIONS 4 Claims, No Drawings [52] U.S. Cl 96/128, 96/127, 96/137, 96/140 [51] Int. Cl. 6031: 1/10 [50] Field of Search 96/104, 106, 102, 105

[56] References Cited UNITED STATES PATENTS 2,41 1,507 1 1/ l 946 Collins et al. 96/104 2,430,558 11/1947 Carroll et al 96/104 3,438,774 4/1969 DePoorter et al. 96/106 Shiro Kimura; Yoshiyuki Nakazawa; Akira Sato; Yasuharu Nakamura, all of Kanagawa,

Primary Examiner-J. Travis Brown Atromey'Sughrue, Rothwell, Mion, Zinn & Macpeak ABSTRACT: A silver halide photographic emulsion containing at least one of the following: 1) a cyanine sensitizing dye represented by the general formula (A) and 2) a merocyanine dye represented by the general formula (B) The dyes have at least one benzimidazole nucleus in which one hydrogen atom of the benzene ring forming the nucleus is substituted by a chlorine atom, and another hydrogen atom of the ring is substituted by a sulfonyl derivative group as shown in the general formulas.

SENSITIZED PHOTOGRAPHIC SILVER HALIDE EMULSIONS BACKGROUND OF THE INVENTION 1 Field of the Invention The present invention relates to a photographic silver halide emulsion containing a cyanine or a merocyanine sensitizing dye and more particularly to a photographic silver halide emulsion containing a cyanine or merocyanine dye having a benzimidazole in which the hydrogen atoms of the benzene nucleus thereof have been substituted with a chlorine atom and a sulfonyl derivative.

2. Description of the Prior Art It is well known in the production techniques of photographic silver halide emulsions that by incorporating a sensitizing dye, such as cyanine or merocyanine to a silver halide emulsion, the light-sensitive wavelength region of the silver halide emulsion is enlarged and also optically sensitized.

However, when a photographic light-sensitive element having the silver halide emulsion layer containing such a sensitizing dye is subjected to the usual processings such as developing, fixing, stabilizing and water-washing, a color stain formed by the sensitizing dye frequently remains in the emulsion layer. The color stain in photographic light-sensitive elements due to the sensitizing dyes causes difficulty in that a print having high whiteness cannot be obtained in black and white photography and good color reproduction cannot be obtained in color photography.

Therefore, as a sensitizing dye to be contained in photographic emulsions, ones causing less color staining after processing are desired.

Therefore, an object of this invention is to provide an improved photographic silver halide emulsion containing an improved sensitizing dye capable of giving a photographic image having good quality, and causing no color staining by the sensitizing dye, after usual photographic processing, such as developing and fixing.

Another object of this invention is to provide an improved sensitizing dye for the photographic silver halide emulsion giving no color stains after processing.

SUMMARY OF THE INVENTION These objects of this invention can be attained by the photographic silver halide emulsion containing at least one of the cyanine sensitizing dyes represented by the general formula and the merocyanine sensitizing dye represented by the general Formula (B) wherein R,, R, and R, each stands for substituent bonded to the nitrogen atom in the above structural formulas, e.g., an

group, a carboxymethyl group, a B-carboxyethyl group, a 'ycarboxypropyl group, B-sulfoethyl group, 'y-sulfopropyl group,

a 8-sulfobutyl group, and an ethyl sulfate group; an allyl group,

an aryl group; and an aralkyl group. R, and R which may be the same or different, each represents a hydrogen atom, a lower alkyl group, and an atomic group necessary for forming a ring such as pyrrolidine, piperidine or morpholine. X represents an anion and Y represents an atomic group necessary for forming a heterocyclic ring, such as a thiazole, a benzothiazole, a naphthothiazole, an oxazole, a benzoxazole, a naphthoxazole, a selenazole, naphthoselenazole, a thiazoline, an oxazoline, a selenazoline, a 2-quinoline, a 4-quinoline, an imidazole, a benzimidazole, and the like. Z represents an atomic group necessary for forming a ketomethylenic heterocyclic ring, such as a pyrazolone, 2,4,fi-triketohexahydropyrimidine, diketohydroindene, hydantoin, thiohydantoin, 2-thio-2,4-oxazolidone, and the like. And,n isOor 1.

As is clear from formulas (A) and (B) mentioned abSriEjiEE feature of the sensitizing dye used in this invention is that the sensitizing dye has at least one benzimidazole nucleus in which one hydrogen atom of the benzene ring forming the benzimidazole nucleus has been substituted with a chlorine atom and another hydrogen atom of the benzene ring has also been substituted with the sulfonyl derivative group as shown in the general formulas.

DETAILED DESCRIPTION OF THE INVENTION below.

Synthesis of lntermediate Compound 1. fi-chloro-l-ethyl- Z-methyl-S-morpholinosulfonyl benzimidazole:

CgHs

lnto 500 ml. of acetone was dissolved 58 g. of 2,4-uichloro- S-nitrobenzene sulfonylchloride followed by ice-cool. Thereafter, a solution of 35 g. of morpholine in 300 ml. of acetone was added dropwise into the solution thus cooled with stirring. After stirring for 1 hour, 1 liter of water was added to the resulting solution and the crystals formed were recovered by filtration. The crystals were washed with water and recrystallized from methanol to provide 45 g. of l,5-dichloro- 4-morpholinosulfonyl-2-nitrobenzene having a melting point of 163 C. The compound thus prepared was caused to react with 17 g. of an aqueous 70 percent monoethylamine solution in 500 ml. of ethanol for 30 minutes under refluxing. The crystals obtained were recovered, washed with water and recrystallized from methanol to provide 40 g. of N-ethyl- 5chloro-4-morpholinosulfonyl-2-nitroaniline. The compound thus obtained was dissolved in 290 ml. of acetic acid and after the addition of 58 g. of acetic anhydride, 56 g. of zinc dust was added little by little with stirring while heating to C. After further continuing the reaction for 2 hours under refluxing by heating, the product was filtered while the system was still hot, the filtrate was concentrated under a reduced pressure, and, after adding an aqueous sodium hydroxide solution to the residue formed to alkalize the product, the product was then extracted by chloroform. When the crude crystals obtained by the extraction were recrystallized from methanol, 265 g. of intermediate compound I having a melting point of 0 w q a nsd Synthesis of Intermediate Compound I], o-chloro-l-ethyl- Z-methyl-S-piperidinosulfonyl benzimidazole:

a benzoselenazole, a

Synthesis of Intermediate III. 6-chloro-l-ethyl-5-N-ethylsulfamyl-2-methylbenzimidazole:

By the same procedure as in the case of preparing Intermediate Compound I, except that monoethylamine was used instead of morpholine, the Intermediate Compound having a melting point of 200 C. was obtained. The melting points of l,5-dichloro4N-ethylsulfamyl-Z-nitrobenzene and N-ethyl-S- chloro-4-N-ethylsulfanyl-2-nitroaniline 5-chloro-4-N formed during the production of Intermediate Compound 11 were 146 C. and 179 C. respectively.

Synthesis of Intermediate Compound IV, 6-chloro-l,3

diethyl-2-methyl-S-morpholinosulfonylbenzimidazolium-ptoluenesulfonate.

Seven grams (7 g.) of Intermediate Compound I, 6-chloro- 1ethyl-2-methyl-5-morpholinosulfonylbenzimidazole was caused to react with 5 g. of ethyl p-toluenesulfonate for 6 hours at 160 C. By treating the reaction product with acetone, after cooling, there was formed 5 g. of the crystals of Intermediate Compound IV having a melting point of 190 C.

Synthesis of Intermediate Compound V, the sodium salt of 6-chloro-l-ethyl-2-methyl-5-morpholinosulfonyl-3-(3-sulfopropyl)benzimidazolium iodide:

Thirty five grams g.) of 6-chloro-l-ethyl-2-methyl-5- morpholinosulfonylbenzimidazole (Intermediate Compound I) was caused to react with 30 g. of sodium iodopropanesulfonate for 6 hours at 170 C. The product was washed thoroughly with acetone and dried to provide the crude I By the same procedure as in the case of preparing Intermediate Compound V, 6-chloro-l-ethyl-2-methyl-5-piperdinosulfonylbenzimidazole (Intermediate Compound 11) was caused to react with sodium iodopropanesulfonate to provide Intermediate VI having a melting point of higher than 250 C. and hygroscopic properties. A

Synthesis of Intermediate Compound VII, the sodium salt of 6-chloro-l-ethyl-5-N-ethysulfamyl-2-methy1-3-(3-sulfopropyl) benzimidazolium iodide:

| on. omt-q z-s 0, F/

caHssoaNa I By the same procedure as in the case of preparing Intermediate Compound Y except that Intermediate Compound III was used instead of using Intermediate Compound I, there was obtained Intermediate Compound VIII having a melting point of higher than 250 C. and hygroscopic properties.

Synthesis of Sensitizing Dye I having the following structure:

Intermediate Compound V1 (3.2 g.) mentioned above was caused to react with 2.2 g. of Z-(B-acetovinyl)-3-ethylbenzoxazolium iodide in a mixed solvent of 20 ml. of nitrobenzene, one ml. of acetic anhydride, and 2 ml. of triethylamine for 15 minutes by heating under refluxing. After cooling the product, ether was added to the system to precipitate the product, which was washed with ether and mixed with water to precipitate the crystal of the product. Crystals were recovered by filtration, washed with water and recrystallized from a mixed solvent of methanol and chloroform to provide 1.3 g. of the sensitizing dye having a melting point of 29 1 C. The spectral absorption maximum of the product in methanol was 492 m Synthesis of Sensitizing Dye 11 having the following structure:

Two grams (2 g.) of Z-(B-anilinovinyl)-3-ethyl-5-methylbenzoxazolium iodide was refluxed by heating for 10 minutes in a mixed solvent of 20 ml. of nitrobenzene and 2 ml. of acetic anhydride. Into the resulting solution were added 2.8 g. of Intermediate V 11 prepared above and 2 ml. oftriethylamine and the reaction was conducted for 10 minutes by heating under refluxing. By processing the product as in the case of preparing Sensitizing Dye I, l g. of Sensitizing Dye II having a i melting point of 284 C. was obtained. The spectral absorption maximum of the dye in methanol was 496 mu.

Synthesis of Sensitizing Dye III having the structure:

(III) In a mixed solvent of 25 ml. of nitrobenzene and 2 ml. of acetic anhydride was refluxed 2.6 g. of 2-(B-anilinovinyl)-3- ethyl-5-phenyl-benzoxazolium iodide for minutes by heating. Into the solution were added 3.2 g. of Intermediate Compound V and 2 ml. of triethylamine, and the reaction of the system was conducted for 10 minutes under refluxing by heating. By processing the product as in the case of preparing Sensitizing Dye I, 1.2 g. of Sensitizing Dye III having a melting point of higher than 300 C. was obtained. The spectral absorption maximum of the dye in methanol was 499 mu.

Synthesis of Sensitizing Dye IV having the following structure:

Intermediate Compound V (3.2 g.) was. caused to react with 2 g. of Z-(B-acetanilinovinyl)-3-ethylthiazolium iodide in a mixture of ml. of nitrobenzene, one ml. of acetic anhydride and 2 ml. of triethylamine for 10 minutes by heating under refluxing. The product was processed as in the case of preparing Sensitizing Dye I and the product was recrystallized from ethanol to provide 1.] g. of Sensitizing Dye IV having a melting point of 246 C. The spectral absorption maximum of the dye in methanol was 477 mp.

Synthesis of Sensitizing Dye V having the following structure:

Intermediate Compound V I (3.2 g.) was caused to react with 2.3 g. of 2-(B-acetanilinovinyl)-I,3,3-trimethylindolenium iodide in a mixture of 20 ml. of nitrobenzene, 1 ml. of acetic anhydride and 2 ml. of triethylamine for 10 minutes by heating under refluxing. The product was processed as in the case of preparing Sensitizing Dye I and the crystals thus obtained were recrystallized from a mixed solvent of ethanol and isopropanol to provide 0.8 g. of Sensitizing Dye V having melting point of 223 C. The spectral absorption maximum of the dye in methanol was 10 my.

Synthesis of Sensitizing Dye VI having the following structure:

In a mixture of 20 ml. of nitrobenzene and 2 ml. of acetic 0 anhydride was heated 2.5 g. of 2-(B-anilinovinyl)-5,6-

dichloro-I,3-diethylbenzimidazolium iodide for 15 minutes under refluxing. Into the solution were added 3 g. of Intermediate VII and 2 ml. of triethylamine and the system was reacted for 15 minutes by heating under refluxing. By treating the product as in the case of preparing Sensitizing Dye I, 0.7 g. of Sensitizing Dye VI having a melting point of 228 C., was I obtained. The spectral absorption maximum of the product in methanol was 5 l9 mu.

Synthesis of Sensitizing Dye VII having the following struc- In a mixture of 20 ml. of nitrobenzene and 2 ml. of acetic anhydride was refluxed 2.5 g. of 2-(B-anilinovinyl)-5,6- dichloro-l,3-diethylbenzimidazolium iodide for 15 minutes by heating under refluxing. The solution was then mixed with 3.2 g. of Intermediate Compound V and 2 ml. of triethylamine and the system was reacted for IS minutes by heating under refluxing. By treating the product as in the case of preparing Sensitizing Dye l.(l.9 g. of Sensitizing Dye Vll having a melting point of 233 C. was obtained. The spectral absorption maximum of the dye in methanol was 5 l 9 mu.

Synthesis ofsensitizing dye VIII having the structure:

Intermediate Compound IV (4.5g.) was caused to react with I5 ml. of ethyl ortho-formate in a mixture of 30 ml. of nitrobenzene and 3 ml. of triethylamine for 15 minutes by heating under refluxing. After cooling, ether was added to the reaction mixture to precipitate the product, which was washed with ether. The product was dissolved in a small amount of methanol and after adding a methanol solution containing an excessive amount of sodium iodide, the solvent was removed to form a crystal, which was washed with water and recrystallized from a mixed solvent of methanol and chloroform to pr9 v vide l.8 g. of Sensitizing Dye VIII having a melting point of 263 C. The spectral absorption maximum of the dye in methanol was 518 mu.

Synthesis of Sensitizing Dye IX having the following structure:

I OH; N

CH: N-S 0, N

intermediate Compound V1 (3.2 g.) was caused to react with 1.2 g. of l-ethy1-2-ethylmercapto-6-methylquinoliumethyl sulfate in a mixture of 50 ml. of ethanol and 1 ml. of triethylamine for 20 minutes by heating under refluxing. Ether was added to the product solution to precipitate the dye, which was then purified by recrystallization from a mixed solution of ethanol and methanol. The spectral absorption maximum of the dye in methanol was 452 mu.

The sensitizing dyes used in this invention are novel compounds. Photographic silver halide emulsions containing such sensitizing dyes have advantages such that the silver halide emulsion layer of a photographic light-sensitive element scarcely causes color staining on the image due to the dye remaining after the photographic element is subjected to photographic processing, such as, developing, fixing and waterwashing. Also, the sensitizing property of the dye in a photographic silver halide emulsion is not reduced when other materials, such as, a surface active agent, a coupler, and other compounds having anionic groups are present in the same emulsion, since the coaction of the dye with such compounds is small.

The novel sensitizing dye of this invention can sensitize spectrally a silver halide emulsion containing it and in particular can effectively enlarge the spectral light-sensitive region of a gelatino silver halide emulsion. Moreover, the sensitizing dye of this invention can sufficiently sensitize photographic emulsions containing other hydrophilic colloids than gelatin, such as, agar agar, collodion, a water-soluble cellulose derivative, polyvinyl alcohol, and other hydrophillic synthetic and natural resins.

In the photographic silver halide emulsion of this invention,

various silver salts, such as, silver chloride, silver bromide,

silver iodide, silver iodobromide, silver chlorobromide, and silver chloroiodobromide may be employed.

The sensitizing dye used in this invention can be incorporated into a photographic silver halide emulsion of which the whole sensitivity has been physically and chemically .sensitized.

In order to prepare the photographic silver halide emulsion of this invention, one or more sensitizing dyes in this invention may be incorporated in a photographic silver halide emulsion by a conventional manner. In practice, the sensitizing dye is usually added to a photographic silver halide emulsion as a solution thereof in a proper solvent.

The amount of the sensitizing dye to be incorporated in an emulsion may be varied in a wide range of l-l50 mg. per one kg. of the emulsion.

The photographic silver halide emulsion of this invention may further be subjected to hyper-sensitization and super-sensitization. Furthermore, in the case of preparing the photographic silver halide emulsion of this invention, there may be added therein, in a conventional manner, the usually employed additives, such as, sensitizers, stabilizers, color toning agents, hardening agents, wetting agents, antifoggants, plasticizers, developing promoters, couplers, and fluorescent whitening agents.

The photographic silver halide emulsion of this invention may be applied to a proper support, such as, a glass plate, a

, film of a cellulose d erivative, a film of a synthetic resin or a baryta paper, in the usual manner.

Examples of the practice of this invention are given below.

EXAMPLE A photographic emulsion was prepared by adding the sensitizing dye of this invention to a silver iodobromide emulsion (Agl:AgBr--7:93 in mol ratio) or a silver chlorobromide emulsion (AgBr:AgCl=40:60 in mol ratio). The photographic emulsion was applied to a film base of triacetyl cellulose and dried. The photographic light-sensitive film was exposed through a Fuji number 3 filter (passing light having wavelength longer than 500 my.) to daylight of 64 lux (5,400 K) and developed. in the development, the developer having the composition shown in table 1 was used for the silver iodobromide emulsion and the developer having the composition shown in table 2 was used for the silver chlorobromide emulsion. The results are shown in table 3 and table 4.

TABLE 1 N-Methyl-p-aminophenol sulfate 20 g. Hydroquinone 5.0 g. Sodium sulfite I00 5. Borax 20 g. Water to make L000 ml.

TABLE 2 N-Methyl-p-aminophenol sulfate 20 g. Hydroquinone 4.0 g. Sodium sulfite 40 g. Sodium carbonate (anhydrous) 40 g. Potassium bromide 24 8- Water to make L000 rnl TABLE 3 Test Kind of Sensitization Sensi- Dye (A) Emulsion Maximum (mp) itivity l 0.08 AgBr/l 530-535 362 2 ll 0.08 AgBr/l 540-545 450 3 III 0.06 AgBr/l 542 388 4 IV 0.06 AgBr/I 514 246 5 V 0.08 AgBr/l 548-550 670 6 V] 0.08 AgBr/l 564-568 950 7 V" 0.08 AgBr/l 560-568 900 8 V [11 0.08 AgBr/l 570 720 9 l 0.08 AgCl/Br 510-520 370 10 ll 0.08 AgCl/Br 510-530 300 lll 0.08 AgCl/Br 535-540 324 ,2 IV 0.08 AgCl/Br 510 105 13 V 0.08 AgCl/Br 550 I75 4 VI 008 AgCl/Br 570 350 is Vll 0.08 AgCl/Br 570 335 16 1X 0.08 AgCl/Br 560-570 290 The sensitivity was calculated by assuming the sensitivity of a silver halide emulsion containing no dye as 100. In the AgCl/Br emulsion, the sensitivity value without using filter was used while in the AgBr/l emulsion, the sensitivity under Fuji number 3 filter (made by Fuji Shashin Film K.K.; passing light having wavelength longer than 500 mu).

TABLE 4 Test Kind of Dye Mg-mollkg Emulsion Emulsion Color Stain Ill 0.06 AgBr/l 0.04

X1 0.06 AgBr/l 0.14

Vll 0.08 AgBr/l 0.04

xu 0.0a AgBr/l 0.68

IX 0.08 AgCl/Br 0.05

Xlll 0.08 AgCl/Br 0.08

(' ):Comparative sensitizing dyes have below showing structures.

The tests shown in table 4 were conducted by fi'sifi the samples which had been developed in the unexposed state, fixed for 10 minutes, washed with water for 29 minutes at 16 C., and dried. The value of Color Stain shown in the table was the density of the film under Fuji number 17 filter (made by Fuji Shashin Film K.K.) having a maximum transmission at 525 The conventional sensitizing dyes used as control dyes are as follows: m I

sensitizing Dye XI What is claimed is:

1. A photographic silver halide emulsion containing at least one member selected from the sensitizing dyes represented by the general formulas:

wherein R R and R each represents a member selected from the group consisting of an alkyl group, a hydroxyalkyl group, an acetoxyalkyl group, a carboxyalkyl group, a sulfoalkyl group, an ethysulfate group, an allyl group, an aralkyl group and an aryl group; R and R,,, which may be the same or different, each represents a member selected from the group consisting of a hydrogen atom, a lower alkyl group, and a ringforming atomic group selected from the group consisting of ring-forming atomic groups based on pyrrolidine, piperidine and morpholine; Y represents an atomic group forming a member selected from the group consisting of S-membered and 6-membered nitrogen-containing heterocyclic rings as are used in the cyanine dye art; X represents an anion, n, and n, each represents 0 or I; and Z represents an atomic group forming a ketomethylene heterocyclic ring selected from the group consisting of a pyrazolone, 2,4,6-triketohexahydropyrimidine, diketohydroindene, rhodanine, hydantoin, thiohydantoin and 2-thio-2,4-oxazolidone group.

2. The emulsion of claim 1 wherein said alkyl group is selected from the group consisting of a methyl group, an ethyl group and a propyl group; said hydroxyalkyl group is a B- hydroxyethyl group, said acetoxyalkyl group is selected from the group consisting of a B-acetoxyethyl group and a y-acetoxy propyl group, said carboxyalkyl group is selected from the group consisting of a carboxymethyl group, a B-carboxyethyl group and a y-carboxypropyl, and said sulfoalkyl group, is

selected from the group consisting of a B-sulfoethyl group, a ysulfopropyl group and a 'y-sulfobutyl group.

3. The emulsion of claim 1 wherein said heterocyclic ring completed by Y is selected from the group consisting of a thiazole, a benzothiazole, a naphthothiazole, an oxazole, a benzoxazole, a naphthoxazole, a selenazole, a benzoselenazole, a naphthoselenazole, a thiazoline, an oxazoline, a selenazoline, a 2-quinoline a 4-quinoline, an imidazole and a benzimidazole group.

The emulsion of claim 1 wherein said sensitizing dye is selected from the group consisting of 

2. The emulsion of claim 1 wherein said alkyl group is selected from the group consisting of a methyl group, an ethyl group and a propyl group; said hydroxyalkyl group is a Beta -hydroxyeThyl group, said acetoxyalkyl group is selected from the group consisting of a Beta -acetoxyethyl group and a gamma -acetoxy propyl group, said carboxyalkyl group is selected from the group consisting of a carboxymethyl group, a Beta -carboxyethyl group and a gamma -carboxpropyl group, and said sulfoalkyl group is selected from the group consisting of a Beta -sulfoethyl group, a gamma -sulfopropyl group and a gamma -sulfobutyl group.
 3. The emulsion of claim 1 wherein said heterocyclic ring completed by Y is selected from the group consisting of a thiazole, a benzothiazole, a naphthothiazole, an oxazole, a benzoxazole, a naphthoxazole, a selenazole, a benzoselenazole, a naphthoselenazole, a thiazoline, an oxazoline, a selenazoline, a 2-quinoline, a 4-quinoline, an imidazole and a benzimidazole group.
 4. The emulsion of claim 1 wherein said sensitizing dye is selected from the group consisting of 